Plant & Animal Genomes XI Conference

January 11-15, 2003
Town & Country Convention Center
San Diego, CA

Poster: Gene Isolation
            

RICE GENOME AS A TOOL FOR CLONING ALUMINUM TOLERANCE GENE IN RYE (SECALE CEREALE L.)

¹ Department of Agronomy, University of Missouri-Columbia, 307 Curtis Hall, Columbia, MO 65211, USA

² USDA, ARS and Department of Agronomy, University of Missouri-Columbia, 206 Curti Hall, Columbia, MO 65211, USA

The use of aluminum (Al) tolerant varieties has been considered as a solution to overcome the problem of Al toxicity in acid soils, but development of such varieties demands basic knowledge of tolerance mechanisms, which are not well understood. Characterizing gene/s controlling Al tolerance in plants could be a possible way to elucidate Al tolerance mechanisms, however none of the genes has yet been cloned. In an attempt to clone the Al tolerance gene from rye, the most Al-tolerant grass species, we utilized a map based-clone technique and the rye/rice syntenic relationship. Genetic analysis of a rye F₆ RIL population revealed a single dominant gene (Alt3) located on the long arm of chromosome 4. Three AFLP markers flanking the gene and one RFLP marker co-segregating with Alt3 were identified. Syntenic analysis suggested that the Alt3 region was co-linier with a region of chromosome 3 in rice. Two STS flanking markers developed from a rice BAC clone facilitated the construction of a high-resolution map of the Alt3 region. By screening RFLP markers developed from the rice BAC clone and mapping them into an F₂ population (2246 gametes) segregating for Alt3, we constructed a high resolution map of the Alt3 region with one co-segregating marker and two flanking markers 0.1 cM apart. The Alt3 region spanning the flanking markers covers 10 kb region of the rice BAC clone that contains four candidate genes. One of the candidate genes is expressed only in an Al-stressed Al-tolerant line.